If you need the textual date, "date", will suffice.
If you need it in RFC2822, "date -R" will do that.
If you need it in unix format, "date +"%s" will do that.
And finally, a format the fits well with file names is "date +"%F"
Examples:
$ date
Mon 23 Jun 08:45:15 BST 2014
$ date -R
Mon, 23 Jun 2014 08:45:18 +0100
$ date +"%s"
1403509524
$ date +"%F"
2014-06-23
To enter any of these in the command line:
touch hi_$(date +"%F")_there.txt